Evaluation of Genome-Wide Expression Profiles of Blood and Sputum Neutrophils in Cystic Fibrosis Patients Before and After Antibiotic Therapy

• DOI: 10.1371/journal.pone.0104080
• Publication Date: 2014-08-01T23:04:44Z
• Authors: Massimo Conese; Stefano Castellani; Silvia Lepore; Orazio Palumbo; Antonio Manca; Teresa Santostasi; Angela Maria Polizzi; Massimiliano Copetti; Sante Di Gioia; Valeria Casavola; Lorenzo Guerra; Anna Diana; Pasqualina Montem...; Maria Addolorata ...; Crescenzio Gallo; Angela Bruna Maff...; Massimo Carella
• Keywords: Adult; Male; Adolescent; Cystic Fibrosis; Neutrophils; Science; tobramycin; Down-Regulation; Real-Time Polymerase Chain Reaction; phorbol 13 acetate 12 myristate; 03 medical and health sciences; minocycline; ciprofloxacin; meropenem; amikacin; Humans; antibiotic agent; ceftazidime; Child; Lung; Demography; Oligonucleotide Array Sequence Analysis; azithromycin; Inflammation; teicoplanin; 0303 health sciences; C reactive protein; Genome, Human; Gene Expression Profiling; Q; R; Reproducibility of Results; beta arrestin 1; cotrimoxazole; Anti-Bacterial Agents; Respiratory Function Tests; 3. Good health; antiinfective agent; Case-Control Studies; Medicine; Female; Research Article

In seeking more specific biomarkers of the cystic fibrosis (CF) lung inflammatory disease that would be sensitive to antibiotic therapy, we sought to evaluate the gene expression profiles of neutrophils in CF patients before treatment in comparison with non-CF healthy individuals and after antibiotic treatment. Genes involved in neutrophil-mediated inflammation, i.e. chemotaxis, respiratory burst, apoptosis, and granule exocytosis, were the targets of this study. Microarray analysis was carried out in blood and airway neutrophils from CF patients and in control subjects. A fold change (log) threshold of 1.4 and a cut-off of p<0.05 were utilized to identify significant genes. Community networks and principal component analysis were used to distinguish the groups of controls, pre- and post-therapy patients. Control subjects and CF patients before therapy were readily separated, whereas a clear distinction between patients before and after antibiotic therapy was not possible. Blood neutrophils before therapy presented 269 genes down-regulated and 56 up-regulated as compared with control subjects. Comparison between the same patients before and after therapy showed instead 44 genes down-regulated and 72 up-regulated. Three genes appeared to be sensitive to therapy and returned to "healthy" condition: phorbol-12-myristate-13-acetate-induced protein 1 (PMAIP1), hydrogen voltage-gated channel 1 (HVCN1), and β-arrestin 1 (ARRB1). The up-regulation of these genes after therapy were confirmed by real time PCR. In airway neutrophils, 1029 genes were differentially expressed post- vs pre-therapy. Of these, 30 genes were up-regulated and 75 down-regulated following antibiotic treatment. However, biological plausibility determined that only down-regulated genes belonged to the gene classes studied for blood neutrophils. Finally, it was observed that commonly expressed genes showed a greater variability in airway neutrophils than that found in blood neutrophils, both before and after therapy. These results indicate more specific targets for future interventions in CF patients involving respiratory burst, apoptosis, and granule exocytosis.